Effect of heat treatment on microstructure and dimensional stability of ZL114A aluminum alloy

The effects of heat treatment process on microstrucature, micro-yield strength and dynamic dimensional stability of ZL114A aluminum alloy were investigated by optical microscopy （OM）, transmission electron microscopy （TEM）, tensile testing and thermal cycling on-line measuring method. Fine dispersed eutectic Si phases are observed, and long strip eutectic Si and massive primary Si phases decrease in ZL114A alloy after high-temperature and long-time solution treatment, which result in the increase of micro-plastic deformation resistance. With the increasing of aging temperature, aging precipitation behaviour of ZLll4A alloy transforms from precipitation of GP zone and fl＇ phases simultaneously at lower temperature to precipitation of stable Mg2Si phases at higher temperature. Because coherent strengthening is the main strengthen mechanism for micro-plastic deformation, precipitation of stable Mg2Si phases is unfavorable to the improvement of micro-plastic deformation resistance. Micro-yield strength cannot characterize dimensional stability comprehensively, and dynamic dimensional stability under alternative temperature should also be tested cooperatively for better evaluation of dimensional stability.

Three-dimensional stability of landslides based on local safety factor

Unlike the limit equilibrium method(LEM), with which only the global safety factor of the landslide can be calculated, a local safety factor(LSF) method is proposed to evaluate the stability of different sections of a landslide in this paper. Based on three-dimensional(3D) numerical simulation results, the local safety factor is defined as the ratio of the shear strength of the soil at an element on the slip zone to the shear stress parallel to the sliding direction at that element. The global safety factor of the landslide is defined as the weighted average of all local safety factors based on the area of the slip surface. Some example analyses show that the results computed by the LSF method agree well with those calculated by the General Limit Equilibrium(GLE) method in two-dimensional(2D) models and the distribution of the LSF in the 3D slip zone is consistent with that indicated by the observed deformation pattern of an actual landslide in China.

Slope stability analysis of Balia Nala landslide, Kumaun Lesser Himalaya, Nainital, Uttarakhand, India

Balia Nala is the outlet of the Nainital lake, flowing towards southeast direction. Presence of Nainital habitation at its right bank has high socio-economic importance. This study presents the stability analysis of a ravine/valley along Balia Nala. Variegated slates(lower Krol and upper Blaini formations) are the main rock types, wherever the outcrop does exist and rest of the area is covered by slope wash and river borne materials. Three sets of joints are presented in the area, but 4 sets of joints also exist at some locations. Nainital lake fault intersected by Manora fault from southwest direction passes through eastern side of the study area, and some small faults, which are sub-branches of Nainital lake fault, are observed(with 10 m offset) and promote the landslide in the area. This study shows that different kinds of discontinuities(joints, faults and shear zones) and rapid down cutting by the stream due to neotectonic activity affect the stability of the slope. The fragile lithology and deep V-shaped valley further accelerate the mass movement in the study area. In addition, rock mass rating(RMR), factor of safety(FOS) and graphical analysis of the joints indicate the study area as landslide-prone zone. This study will be helpful in not only reducing the risk on life of people, but also in assisting the ongoing civil work in the study area.

Decay resistance and dimensional stability improvement of wood by low melting point alloy heat treatment

Wood has no inherent natural resistance against agents of biodegradation. We evaluated the effects of metal bath heat treatment(MBHT) on decay resistance and dimensional stability of Chinese parasol(Firmiana simplex) and Chinese fir(Cunninghamia lanceolata) wood. A low melting point alloy was used as heating medium in the treatment of the wood samples at 150, 180, and 210 °C for2, 4, and 8 h. Heat-treated and control samples were exposed to brown rot fungus(Poria placenta) and white rot fungus(Coriolus versicolor) for decay resistance testing and anti-swelling efficiency(ASE). The improved decay resistance with increase temperatures with low mass losses of 7.3 and 7.3% for F. simplex, and 3.9 and 3.6% for C.lanceolata at 210 °C for 8 h against Coriolus versicolor and Poria placenta, respectively. ASE indicated that MBHT contributed to improved dimensional stability of both wood species after treatment. Scanning electron micrograph results indicate that metal bath-treated samples showed strong decay resistance. Therefore, our approach to thermally modify wood should be explored to overcome the energy utilization by using low melting point alloy for the heat treatment of wood.

Landslide stability for Shuitianba in the Three Gorges area

According to the data of preliminary survey, the authors established a landslide geological model,on the basis of analyses on the sensitivity of landslide, tried to simulate and calculate the landslide stability of Shuitianba with the method of transfer coefficient when it is under different strength parameters, and study the landslide mechanism. The results show that it is sensitive to the effects of shear strength parameters of sliding zone and groundwater level on landslide stability safety coefficient, which provides reliable basis for calculation of landslide stability.

Effects of Heat Treatment on Dimension Stability of Larch Pallet Decks

The useful life of wooden pallets is lower because of the defects in lumbers. The quality of lumber can be significantly enhanced by heat treatment. In this paper,the larch pallet decks samples were heat-treated under the conditions of different time and temperatures. The quantity of water uptake has reduced 16. 8% under the condition of 250 ℃ for 150 min. The resistance of water absorption efficiency increases 165. 34% under the condition of 175 ℃ for 90 min. The anti-shrink efficiency increases 72. 08% under the condition of 250 ℃ for 90min. The results showed that the dimension stability of larch panels can be improved by heat treatment. The condition of 250 ℃ for 180 min is the best heat treating condition to improve the dimension stability.

THE EFFECT OF ACID TREATMENT ON THE STABILITY OF POLYMORPHS IN BETA ZEOLITE

The stability of beta zeollie in acid solution and the effect of acid treatment on the polymorphs in beta zeolite were studied. This zeolite is easily dealuminated by HCI treatment but its framework highly resistent to acidity.In β zeolite, polymorph A is less stable than polymorph B.The chirality of β zeolite can be modified by the method of acid treatment.

Engineering Geological and Geotechnical Studies of Taprang Landslide, West-central Nepal: An Approach for Slope Stability Analysis

Detailed investigation of Taprang landslide was carried out in order tounderstand the surface, subsurface lithological information and physicalproperties of soil by using multi-disciplinary methods such as engineeringgeological, geophysical and geotechnical studies for the determinationof factor of safety for slope stability analysis. Geological study wascarried out by detail mapping of surface geology, soil condition, propertiesof bedrock and its discontinuities. The geophysical survey (ElectricalResistivity Tomography-ERT) were carried out to know the electricalresistivity of soil for identifying the groundwater table and slip surface ofthe landslide. Geotechnical analysis such as grain size analysis, liquid limitand direct shear test were carried out in order to evaluate soil classification,moisture content, cohesion and the angle of internal friction of soil forknowing the strength the soil. These soil parameters indicate the soil is verylow strength. The combination of these results were used for calculatingthe factor of safety (FoS) by Limit Equilibrium Method (LEM) proposedby Bishop and Janbu methods. The result of factor of safety in the Tapranglandslide demonstrates that the slope become stable in drained (dry)condition, remain ultimate stage in undrained (wet) condition and finallyfailure occurs if applied the seismic load in both drained and undrainedconditions.

Early warning system for shallow landslides using rainfall threshold and slope stability analysis

A combined cluster and regression analysis were performed for the first time to identify rainfall threshold that triggers landslide events in Amboori, Kerala, India. Amboori is a tropical area that is highly vulnerable to landslides. The 2, 3, and 5-day antecedent rainfall data versus daily rainfall was clustered to identify a cluster of critical events that could potentially trigger landslides. Further, the cluster of critical events was utilized for regression analysis to develop the threshold equations. The 5-day antecedent(xvariable) vs. daily rainfall(y-variable) provided the best fit to the data with a threshold equation of y = 80.7-0.1981 x. The intercept of the equation indicates that if the 5-day antecedent rainfall is zero, the minimum daily rainfall needed to trigger the landslide in the Amboori region would be 80.7 mm. The negative coefficient of the antecedent rainfall indicates that when the cumulative antecedent rainfall increases, the amount of daily rainfall required to trigger monsoon landslide decreases. The coefficient value indicates that the contribution of the 5-day antecedent rainfall is～20% to the landslide trigger threshold. The slope stability analysis carried out for the area, using Probabilistic Infinite Slope Analysis Model(PISA-m), was utilized to identify the areas vulnerable to landslide in the region. The locations in the area where past landslides have occurred demonstrate lower Factors of Safety(FS) in the slope stability analysis. Thus, rainfall threshold analysis together with the FS values from slope stability can be suitable for developing a simple, cost-effective, and comprehensive early-warning system for shallow landslides in Amboori and similar regions.

Effect of oxidation treatment on the adsorption and the stability of mercury on activated carbon

Oxidation treatment on the adsorption and the stability of Hg on activated carbon （AC） was inrestigated. Both MnO2-AC and FeCl3-AC were produced during oxidation treatment. The measurement of modified AC＇s mercury adsorption capacity was conducted in a simulated coal-fired flue gas by adsorbing test apparatus. TCLP and column leaching methods were used to test the stability of mercury adsorbed on ACs. The results indicate that the oxidation treatment changed the pore structure of the AC and modified the carbon surface by creating chemical components such as MnO4^-, Mn^4＋, O, NO^3-, Fe^3＋, Cl^-, etc. The Hg sorption capacity on MnO2-AC or FeCl3-AC was about three times higher than that of untreated carbon. In addition, the mercury control cost of each of the formers was about the half cost of the untreated carbon. The stability of Hg absorption was studied, it found that mercury adsorbed on the oxidation treated AC was not better than that of untreated carbon. It could concluded that the insoluble form of Hg is very important to the stability of mercury adsorbed on AC. This study suggests that the FeCl3-AC is the best absorbent for Hg with high adsorption capacity, better Hg adsorption stability in leaching environment, and lower cost among the three ACs tested.

A multi-objective decision-making method for the treatment scheme of landslide hazard

The treatment engineering of landslide hazard is a complicated systemengineering. The selecting treatment scheme is influenced by many factors such as technology,economics, environment, and risk. The decision-making of treatment schemes of landslide hazard is aproblem of comprehensive judgment with multi-hierarchy and multi-objective. The traditional analysishierarchy process needs identity test. The traditional analysis hierarchy process is improved bymeans of optimal transfer matrix here. An improved hierarchy decision-making model for the treatmentof landslide hazard is set up. The judgment matrix obtained by the method can naturally meet therequirement of identity, so the identity test is not necessary. At last, the method is applied tothe treatment decision-making of the dangerous rock mass at the Slate Mountain, and its applicationis discussed in detail.

Slope stability evaluation and monitoring of a landslide: a case study from NE Turkey

Landslides are quite common natural hazards in the eastern Black Sea region of NE Turkey.Following the heavy rainfall in the K?prülü(Rize)village settlement area,located in this region where the slope debris overlies the agglomerates,a failure occurred.Due to the developed tension cracks and deformations on the ground,houses,tea gardens,and roads were damaged completely.To figure out the causes and mechanism of the sliding and to suggest the precautions,a detailed geotechnical study was carried out.Along the five survey lines,twelve boreholes were drilled with a total depth of 300 meters.Also,the geophysical surveys on ten profiles were conducted and the inclinometer measurements were taken in five boreholes.Undisturbed and disturbed samples were collected and laboratory experiments were performed.Inclinometer measurements indicated that the sliding started in the slope debris and then spread to the agglomeratic bedrock.The slope stability was examined using the limit equilibrium(LE)and finite element(FEM)analysis methods.The results of the slope stability analyses showed that the failure mode is talus slide with composite shape and outputs coincide with the inclinometer monitoring results.Based on the collected data,it is determined that there will be unavoidable engineering problems if no precautions are taken.Because of the negative reasons which make the application of supporting methods meaningless in the study area,it is considered that transferring the residences to a safer place without risk of natural hazards will be economical and reliable.

Investigating a potential reservoir landslide and suggesting its treatment using limit-equilibrium and numerical methods

A reservoir landslide not only reduces the water storage capacity, but also causes extensive damages to the dam body, power/water transmission lines, roads, and other infrastructures. The Latian Dam, located 35 km north east of Tehran （Iran）, is one of the cases which has encountered serious problems with instability of its rock abutments. This paper addresses the stability analysis of the right abutment of the Latian Dam using limit equilibrium and numerical methods. Geomechanical characteristics of the rock abutment were first estimated based on engineering classification of the rock mass. Different search methods were examined for locating the critical circular/non-circular slip surface in conjunction with the general limit equilibrium method. The effect of variabi]ity of rock mass properties, water table, and earthquake load on the factor of safety （FS） and probability of failure （PF） was studied. In the event of rapid drawdown in the reservoir, the limit equilibrium analysis calculated FS=1.067 and PF=21.1%, and the numerical analysis returned FS=1.01. The results of the analyses suggest that the right abutment of the Latian Dam is prone to slide and needs treatment. Investigations demonstrated that a slope reduction by 15° at the upper part of the abutment would meet stability conditions even in the worst-case scenario （FS=1.297 and PF=2.07%）.

Spatially resolved micron-scale wrinkle structures at asphaltene films induced by mild thermal treatment and its impact on emulsion stability

Mild thermal treatment is an important partial upgrading technique to enable bitumen pipeline transportation,but no attention has been paid to the impact of mild thermal treatment on the emulsification behavior of emerging partially upgraded bitumen.Asphaltene compounds are active emulsion stabilizers in bitumen oil.The emulsion stabilizing capacity of bitumen asphaltenes was investigated,before and after a mild thermal treatment at 400℃.The structural morphology and mechanical property of the asphaltene interfacial films were analyzed by using a combination of cryo-SEM,Langmuir trough,and Brewster angle microscopy.The thermal treatment significantly enhanced the emulsion stabilizing capacity of bitumen asphaltenes;the interfacial films formed by the thermally treated asphaltene samples appeared to be rougher and thicker with more abundant micron-scale wrinkle structures.The interfacial corrugation may intensify the mechanical stability/flexibility of the asphaltene films and consequently strengthen the stability of emulsion droplet.

Slope Stability Analyses of Outang Landslide Based on the Peak and Residual Shear Strength Behavior

Most of the natural and compacted fine-grained soil slopes that are in saturated or unsaturated condition undergo a large deformation prior to reaching failure conditions.Such slopes should be designed taking account of their strain-softening behavior using the residual shear strength (RSS) parameters.In this paper,the slope stability of a recently reactivated Outang landslide near the Three Gorges Dam in China is analyzed based on the RSS parameters of unsaturated soils.In addition,comparisons are provided in the FOS values of slope using both the peak shear strength (PSS) and RSS parameters.Firstly,a series of site investigations of the hydrologic and geologic conditions,ground surface displacements and cracks were described.The PSS and RSS behaviors of the sliding soils derived from a series of direct shear test results performed on saturated and unsaturated soil specimens are summarized.Secondly,a series of slope stability analysis were conducted considering the precipitation and Yangtze River water level variation within a representative period of 7 months,based on the PSS and the RSS properties.In this study,three different scenarios were considered,which include: i) considering only the precipitation with a constant water level;ii) considering only the decrease in water level without rainfall;iii) considering the combination of precipitation and decrease in water level.In each scenario,four steps were included to calculate the values of factor of safety (FOS) at different times.1) A steady-state seepage analysis was conducted with a constant total head at 525 m on the left boundary and 175 m on the slope surface below the Yangtze River water level.The initial pore water pressures were simulated in the slope under no precipitation and variation of water level.2) A specific boundary condition was applied on the slope surface to model the precipitation and Yangtze River water level variation.A transient seepage analysis was conducted to calculate pore water pressures at different times based on the initial pore water pressures.3) The FOS values at different times were calculated by the Morgenstern-Price method taking account of the variation of pore water pressures at different times,using the peak shear strength (PSS) parameters.4) The last step was repeated replacing PSS parameters with RSS parameters.The RSS parameters were lower than the peak values from laboratory’s direct shear test results for the soils in the sliding zones.The reduction in shear strength from peak to residual state under unsaturated soil condition was greater than that for a saturated soil.The FOS decreased almost linearly with time for the scenario in which only the influence of rainfall infiltration was considered.However,the total reduction in the FOS was relatively small.The FOS decreased rapidly at a linear rate with respect to time with a decrease in water level for the scenario in which Yangtze River water level decrease was considered.The FOS reached to a relatively constant value after Yangtze River water level reached the lowest value.The decrease in Yangtze River water level was the dominant factor that contributed to a reduction in the FOS.The FOS was strongly dependent on the development of the phreatic line after the Yangtze River water level reached the lowest value.The FOS calculated by RSS (i.e.FOSR) is less than unity;they were approximately 16% lower in comparison to that calculated by PSS (FOSP).If PSS parameters were used,the slope would still be stable even under the combined influence of precipitation and Yangtze River water level decrease.These results are inconsistent with the field observations.For this reason,the RSS parameters should be taken into account to evaluate reliably the slope stability of the Outang landslide.

Artificial Neural Network Model for Discrimination of Stability of Ancient Landslide in Impounding Area of Three Gorges Project, China

The factors of geomorphology, geological setting, effect of ground water and environment dynamic factors (e.g. rainfall and artificial water recharge) should be integrated in the discrimination of the stability of the ancient landslide. As the criterion of landslide stability has been studied, the artificial neural network model was then applied to discriminate the stability of the ancient landslide in the impounding area of the Three Gorges project on the Yangtze River, China. The model has the property of self adaptive identifying and integrating complex qualitative factors and quantitative factors. The results of the artificial neural network model are coincided well with what were gained by classical limit equilibrium analysis (the Bishop method and Janbu method) and by other comprehensive discrimination methods.

Study on stability and reinforcement of a landslide on Ji'an-Dandong highway

This study clarified the failure mechanism of a landslide on Ji'an-Dandong highway,through the detailed analysis of its geological condition.Then based on the back analysis of the broken landslide,take limit equilibrium method to evaluate the stability of the potential landslide.The result shows that the landslide is lack of safety stock,so anchor rope is designed to reinforce the landslide.

Effects of heat treatment process on thin film alloy resistance and its stability

Alloy thin film for advanced pressure sensors was manufactured by means of ion-beam sputtering SiO2 insulation film and NiCr thin film on the 17-4PH stainless steel elastic substrate. The thin film resistance was respectively heat-treated by four processes. The effects on stability of thin film alloy resistance were investigated, and paramaters of heat treatment that make thin film resistance stable were obtained. The experimental result indicates that the most stable thin film resistance can be obtained when it is heat-treated under protection of SiO2 and N2 at 673 K for 1 h, and then kept at 473 K for 24 h. Pressure sensor chips of high precision for harsh environments can be manufactured by this process.

Thermal Stability and Effect of Heat Treatment on Manganese Doped Silica Borotellurite Glass

Glasses with chemical formula of {[(TeO2)0.7(B2O3)0.3]0.8[SiO2]0.2}1-x{MnO2}x where x = 0.00 ≤ x ≤ 0.05 molar fraction were fabricated using melt quenching technique. The temperature used in the heat treatment process of the glass sample is 600?C. Calorimetric measurement had been carried out to study the thermal properties of the fabricated glass. The crystallization kinetics of the glass system we reexamined under non-isothermal conditions via differential scanning calorimetric (DSC). The glass transition (Tg), onset glass transition (To), maximum crystallization temperature (Tc) and melting temperature (Tm) were determined. Results from DSC proved that the studied glasses have good thermal stability (Ts) in which indicates its high resistance to devitrification. Strong indicator for the glass forming ability of a glass material, Hurby parameter (Kgl) was also calculated in this research.

Effect of Different Treatments on Antioxidative Stability of the Scallop Protein Hydrolysates

Effects of different treatments on the antioxidant activity of scallop protein hydrolysates (SPH) were evaluated using DPPH radical scavenging activity and reducing power. Results showed that the antioxidant activity of SPH had good heating-resistance from 25°C to 65°C. The antioxidant activity of SPH could retain under acidic environment, but rapidly reduced under alkaline conditions. Addition of D-galactose, D-xylose, and D-fructose at 65°C could increase the antioxidant activity of SPH, but no such effect was not observed at this temperature. With the increase of storage time, the antioxidant activity of SPH gradually decreased. Moreover, pepsin digestion treatment slightly reduced the antioxidant activity of SPH, and further trypsin and mixed enzyme (trypsin + chymotrypsin) digestion significantly reduced this activity (p < 0.05). In conclusion, SPH may be used as food ingredients or food supplements in different food fields.